Hydraulic crane



Aug. 10, 1948. w. HARBAUGH HYDRAULIC CRANE 2 Sheets-Sheet 1 Filed Aug. 1; 1946 Y mmvrok. ALTER 1161mm,

Aug. 10, 1948. w. HARBAUGH HYDRAULIC cams 2 Sheets-Sheet 2 Filed Aug. 1, 1946 INVENTOR. Maura Haemuazr,

MZQM

ATTORNEY Patented Aug. 10, 1948 UNITED STATES- PATENT OFFICE HYDRAULIC CRANE Waiter Harbaugh, Indianapolis, Ind. Application August 1, 1848, Serial No. 887,818

10 Claims.

The present invention relates to hydraulic cranes. and while the invention is applicable to hydraulic cranes wherever installed, it is particularly adaptable to installation upon trucks, and therefore it has been so shown and will be so described. The primary object of the invention is to provide, at minimum cost, mechanism which may be effectively used to lift and to shift relatively heavy loads. As particularly embodied in the illustration of the present application, it is admirably adapted for loading and unloading a truck upon which it may be mounted. A further object of the invention is to provide a fluid operated crane, all of whose lifting and shifting operations can be controlled through the manipulation of two simple valves, resulting in elongation and contraction of the boom forming a part oi. the crane. A further obiect of the invention is to provide an organization of the character here under consideration which involves only two operated parts. A still further object of .the invention is to provide an organization of the character here under consideration, devoid of a boom lifting winch. Still further objects of the in.- vention will appear as the description proceeds.

To the accomplishment of the above and related objects, my invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific construction illustrated and described, so long as the scope of the appended claims is not violated.

Fig. 1 is a side elevation of a truck with my im proved hydraulic crane installed thereon;

Fig. 2 is an enlarged sectional view taken substantially on the line 22 of Fig. 1;

Fig. 3 is a horizontal section taken substantially on the line 3-3 of Fig. 2;

Fig. 4 is an enlarged longitudinal section through a control valve forming a feature of my invention;

Fig. 5 is a transverse section therethrough taken substantially on the line 5-5 of Fig. 4; and

Fig. 6 is a reduced, somewhat diagrammatic plan of the truck of Fig. 1, showing a preferred location for the crane of the present invention.

Referring more particularly to the drawings, it will be seen that l. have illustrated a truck indic ted generally by the reference numeral l0 and having a chassis and a bed I I which is preferably substantially rectangular in plan. Mounted at one corner l2 of the bed II, and supported upon a 2 l8, to, constitute a liquid reservoir. Mounted on said element It is a sleeve I8, supported upon the truck bed II, and obviously oscillable about the axis of the element It, said sleeve projecting above frame member i8, is an upstanding element It which may preferably be hollow, as indicated at the open upper end ll of the element It. A pump i8, of any suitable character, is connected to be driven by a power take-off shaft It with which the truck will be provided, and the intake of said pump communicates, as at 28, with the bottom of the reservoir I5.

Secured to a vertical wall of the sleeve it, at any suitable point intermediate its ends, is a bracket 2i mounting a pivot pin 22 upon which is pivotally supported a socket member or cup 28, swingable, relative to the sleeve i8, about the substantially horizontal axis of the pin 22. One end 24 of a cylinder member 28, formed with a longitudinally extending bore 28, is received and secured in said cup 28. Thereby, the inner end 24 of said cylinder member 25 is operatively closed; while the opposite end 21 is open for the telescopic reception of a second member 28 whose inner end 28 functions as a piston head within the bore 28 of the cylinder member 25. At its outer end, the member 28 carries a cap 88 formed to support a journal pin 8! upon which is rotatably mounted a sheave 82. Usually, it will be desirable, in order to avoid the necessity for accurate engagement between the element 28 and the walls of the bore 28, to secure a cup member 88 of rubber, "neoprene," or other suitable flexible material, to the inner end 28 of said member 28. It will be seen that the two members 28 and 28 of the composite boom, generally indicated by the reference numeral 88, cooperate to constitute a fluid motor. The member 28 acts as a piston, and is suitably supported solely by the member 28, which also acts as the cylinder of the fluid motor.

Suitable conduit means, including a flexible section 85, will be provided to connect the outlet of the pump l8 with a valveunit indicated generally by the reference numeral 85. Said unit comprises a casing having an inlet port 81, to which the conduit section 35 is connected, an exhaust port 88, and an outlet port 89, said outlet port being located in a plane removed from the common plane of the inlet and exhaust ports. Piping 40 connects the port 88 with a T fitting ii, to the stem of which is connected a conduit 42 leading to the interior of the reservoir l5. One suitable means for providing this connection is illustrated herein, sleeve l8 being formed with a port 48 above the level of the open top ll of the element It, and the flexible conduit 82 being connected to said port.

shift the valve body accuse Piping 44 opens from suitable valve-45, controlling flow from said piping 44 to piping 48 connectedwith the fltting 4|. When the valve15 is opened, fluid may flow from the cylinder bore 28 through the piping 44. valve 45, piping 48, and conduit 42 to the reservoir l5.

A pipe 41 leads from the valve port 99 to a check vale 48 which, in turn, communicates with thecylinder bore 28. 5

The valve body. indicated generally by the reference numeral 49, is reciprocably mounted in the unit 98 and comprises a land 58 and a land ll spaced from the land 58 by'a groove 52. A spring 59 within the valve housing normally holds the valve body 49 in the position illustrated in Fig. 4. wherein communication between the port 91 and the port 98 is open but the port 99 is closed by the land 50. Mounted upon a suitable hinge pin 54.is a bellcrank lever 55 one arm 58 of which operatively engages the valve body 49, while the other arm 51 is presented for manual manipulation. Oscillation of the lever 55 in a clockwise direction, as viewed from the left in Fig. 4, will 49 against the tendency of the spring 53, tending to bring the land 5| 1 into closing registry with the port 98, and to move the land 58 out of closing registry with the port 99. It will be seen that the designing and proportioning of the valve unit 98 is such that the port 99 begins to open as the port 98 begins to close, so that fluid can be permitted to bleed slowly through the port 99 and intothe cylinder bore 28. while a part of the .fluid being thrown by; the pump l8 continues to be by-passed back to; the reservoir. This arrangement provides for, extremely delicate operation of the fluid motor;

The can 90 is formed to provide two eyelets 58. A cable or cord '59 may be connected to, the valve actuating lever arm 51 and led throughone of the eyelets 58, being provided at its free end with a finger ring 80. The valve 45 is similarly operable by a lever 82 to which may be connected the bore 28 and leads to a I clear that the boom a cable 8| which may be similarly led through the other eyelet 58 and provided at its free end with a finger ring 89. Thereby, provision is madefor manipulation of the valve units 98 and from any station along the length of the boom 94.

Preferably, a cap 84 will be suitably mounted upon'the upper end of the sleeve I 8 to carry a winch 85 which, in the illustrated embodiment of the invention, is manually actuable. but which obviously may be power driven if desired. A cable 88 iswound upon the winch 85 and runs over the sheave 92, preferabl carrying a hook 81 at its free end. 1

It will be clear, from the above description. that, when the power take-oil shaft i9 is being driven, the pump I 8 will operate continuously to withdraw liquid irom the reservoir l5 and to force it through the conduit". with the valve unit 98 in its illustrated condition, that fluid will flow through the port 98 and piping 48, and through. the conduit 42 to the port 49 and back to the reservoir l5. It, now, the lever is swung in a clockwise direction, as viewed from the left in Fig. 4, a part or all of the fluid thrown by the pump l8 will be diverted through the port 99 and pipe 41 to the check valve 48. Assuming that the pump is developing a pressure in excess of that for which'the check valve 48 is set, that fluid will now flow into the cylinder-bore 28 to force the piston element 28 outwardly, thereby elongating the boom 94.

A cable 88 of fixed length has one end connected to the mast (and preferably to the sleeve ele- 4 ment l9 thereof near its top) and has its opposi end connected to an eyelet 88 formed on the cap 98. Thus, the distance between the cap 98 and the point on the mast to which the cable 88 is connected is maintained. Consequently, as the boom elongates, pivot pin 22. Thus elevation of the boom is accomplished, without the provision of a boom lifting winch, purely through the act of elongatin the boom.

Elongation of the boom will be discontinued when the valve body 48 is permitted to return to its illustrated position; and the boom will maintain its new length so long as both valves remain closed. If, now, the valve 45 is opened, fluid will be discharged from the cylinder bore 28 through said valve-and the conduit 42 back to the reservoir l5. thereby permitting the piston element 28 to move inwardly; and the outer end of the boom will be lowered as the boom contracts.

In use, the boom will be lowered to a position somewhat like that illustrated in Fig. 1, the winch.

will be released, and the cable 88 will be drawn out until the hook 81 can be engaged with the article to be loaded onto the truck. It will be can be swung about the axis of the upstanding element somewhat in excess of pointing toward the article to be loaded, the winch 85 is locked, the valve actuating lever'55 is shifted to open the port 99, and the boom will thereby be elongated, whereby its outer end will be lifted, and thus moved toward the axis of the sleeve l8. Such movement will necessarily to which the hook 81 is attached toward the axis of said sleeve. If the article has originally been so far' from the truck that complete elevation of the boom will not bring that article within the boundaries of the bed ll, the boom its most elevated position, the winch 85 is unlocked and as the boom 'is slowly lowered. the winch-is operated to hold the cable 88 taut. When the boom has reached its optimum position, the winch is again locked, and the above-described operation is repeated. This is continued until the article to be loaded is brought under the end of the boom, whereupon the next elevation of the boom will lift the article. Now, the boom and sleeve I8 are swunmabout the axis of the element I 4, until the article is in desired position above the truck bed ll, whereupon the winch 85 is released to lower the article onto the truck bed II.

Preferably, the length of the cable 88 will be substantially equal to the horizontal distance from the position of the mast to the diagonally opposite corner of the bed. With such an arrangement, it will be readily seen. articles may be deposited anywhere on the truck bed ll.

The mounting of the mast at one corner of the truck bed permits the swinging of the boom through a longer are than would otherwise be possible, and further, improves the capacity for load carrying of the truck bed over an arrangement in which the mast is mounted upon the center line of the truck bed.

I claim as my invention:

1. A fluid-operated crane comprising an axially-fixed, upstanding mast and a boom hingedly associated with said mast tocoscillate about a horizontal axis, said boom comprising a hollow memberand a second member telescopically received in said hollow member and projectingbeit must move upwardly about its l4, through an arc With the boom draw the article is stopped inthe walls of said hollow member, a source of fluid under pressure, means for controlling the flow of fluid from said source to the interior said hollow member, means for controlling the flow of fluid from the interior of said hollow member, and an element of fixed length connecting the outer end of said second member with said mast.

2. A fluid-operated crane comprising an axially-fixed, upstanding mast and a boom hingedly associated with said mast at a point spaced below the top of said mast to swing about a horizontal axis, said boom comprising a hollow member closed at its inner end and open at its outer end and a second member telescopically entered in the outer end of said hollow member and pro- Jecting beyond the free end of said hollow member, means for maintaining a fixed distance between the outer end of said second member and the upper end of said mast, the inner end oi said second member being provided with means establishing a sliding fluid seal with the walls of said hollow member, a source of fluid under pressure, means for controlling the flow of fluid from said source to the interior of said hollow member, and means for controlling the flow of fluid from the interior of said hollow member.

3. A fluid-operated crane comprising a mast and a boom, said mast comprising a tubular, vertical liquid reservoir, said boom being hingedly associated with said mast at a point spaced below the top of said mast, said boom comprising a, hollow member closed at its inner end and open at its outer end and a second member telescopically entered in the outer end of said hollow member, means for maintaining a fixed distance between the outer end of said second member and the upper end of said mast, the inner end of said second member being provided with means providing a sliding fluid seal with the walls of said hollow member, a pump, means providing communication between the bottom of said reservoir and the intake for said pump, conduit means connecting the outlet for said pump with the interior of said hollow member, valve means controlling fluid flow through said last-named means, conduit means connecting the interior of said hollow member directly with said reservoir, and valve means controlling fluid flow through said last-named conduit means.

4. A hydraulic crane comprising a mast and a boom, said mast comprising an upstanding element or circular cross section, and a sleeve swivelly supported on said element, a bracket fixed to said sleeve, said boom comprising a hollow member closed at one end, means at the closed end of said hollow member connecting said member to said bracket to swing with respect thereto about a substantially horizontal axis, and a sec-- ond member havin one end telescopically received in the open outer end of said hollow member, means providing a, sliding liquid seal between said members, a source of liquid under pressure, means for controlling the flow of liquid from said source to the interior of said hollow member, means for controlling the flow of liquid from the interior of said hollow member, and means for maintaining a flxed distance between the outer end of said second member and a predetermined point outside said boom.

5. A hydraulic crane comprising a mast and a boom, said mast comprising an upstanding element of circular cross section, and a sleeve swivelly supported on said element, said boom comprising a cylinder member and a piston member telescopically associated therewith, means pivot'ally connecting one end of one of said members to said sleeve for movement relative thereto about a substantially horizontal axis, means tethering the remote end of the other of said members against movement away from a fixed point on said mast, a, source of fluid under pressure, and means for controlling fluid flow from said source into said cylinder member, and out from said cylinder member.

6. The device of claim 5 including a sheave carried at said remote end of said other member. a winch carried on and movable with said sleeve, and a cable wound on said winch and passing over said sheave.

7. In a device of the class described, a base, an upstanding tubular element closed at its bottom and open at its top to provide a liquid reservoir, a sleeve swivelly supported on said element, resting on said ba e and projecting above the open top of said element, a boom pivotally carried by said sleeve for oscillation with respect thereto about a substantially horizontal axis. said boom comprising a cylinder member and a piston member having one end slidably received within said cylinder member, a pump, means providing communication between the bottom of said reservoir and the intake for said pump, conduit means connecting the outlet for said pump with the interior of said cylinder member, valve means controlling fluid flow through said conduit means, a port in said sleeve above the leveloi the upper end of said tubular element, conduit means connecting the interior oi! said cylinder member with said port, and valve means controlling fluid flow through said last-named conduit means.

8. In a device of the class described, a base, an upstanding tubular element closed at its bottom and open at its top to provide a liquid reservoir, a sleeve swivelly supported on said element, resting on said base and projecting above the open top of said-element, a boom pivotally carried by said sleeve for oscillation with respect thereto about a substantially horizontal axis, said boom comprising a cylinder member and a piston member having one end slidably received within said cylinder member, a pump, means providing communication between the bottom of said reservoir and the intake of said pump, a port in said sleeve above the level of the upper end of said tubular element, conduit means connecting the outlet of said pump with said port, valve means interposed in said conduit means and manipulable to divert flow, at times, to the interior of said cylinder, and other valve means manipulable to direct liquid flow from the interior of said cylinder member to said port.

9. For use with an automotive vehicle having a substantia ly rectangular bed, a. prime mover, and a ower take-off, a fluid operated crane comprising an upstanding element fixedly mounted near one corner of said bed, a sleeve swivelly mounted on said element and supported by said bed, a boom comprising a cylinder member and a piston member telescopically received in said cylinder member, one end of one of said members being pivotally mounted on said sleeve for swinging movement relative thereto about a substantially horizontal axis, a cable having a length substantially equal to the horizontal distance from said upstanding element to the diagonally opposite corner of said bed, one end of said cable being secured to said sleeve and the other end of said cable being secured to the remote end or the other of said members, means for applying pressure to a fluid, means connecting said power take-oil! to drive said pressure-applying means, I

conduit means connecting said pressure-applying means to supply fluid under pressure to the interior 01' said cylinder member, valve means controlling fluid flow through said conduit means, and valve means for controlling fluid flow from the interior oi! said cylinder.

'10. The organization or claim 9, including a sheave carried at said remote end of said other member, a winch mounted on and movable with said sleeve, and a cable wound on said winch and running over said sheave.

WALTER HARBAUGH.

8 1 REFERENCES on'nn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 678,188 Macbeth July 9, 1901 849,108 Castagnos Apr. 2, 1907 10; 1,448,814 Norris Mar. 20, 1923 1,636,136 Kernes July 19, 1927 2,196,649 Waite Apr, 9, 1940 2,374,074 Berby et a1. Apr. 17, 1945 2,415,907

Pierce Feb. 18, 1947 

